Table 1. Central composite design for response surface analysis
Exp. No.
1)
Extraction conditions
Ethanol concentration (%)
Extraction time (h)
1
60 (1)
4 (1)
2
60 (1)
2 (-1)
3
20 (-1)
4 (1)
4
20 (1)
2 (-1)
5
40 (0)
3 (0)
6
40 (0)
3 (0)
7
80 (2)
3 (0)
8
0 (-2)
3 (0)
9
40 (0)
5 (2)
10
40 (0)
1 (-2)
1)
The number of experimental conditions by central composite design.